Tangle and neuron numbers, but not amyloid load, predict cognitive status in Alzheimer's disease

Abstract

Examined the relationship between stereologic estimates of Alzheimer's disease (AD)-related pathology and severity of cognitive deficits in brain aging. Previous studies reported substantial contributions of neurofibrillary tangles (NFT), amyloid deposits, and neuronal loss to the development of dementia. Clinicopathologic study in 22 elderly cases. Cognitive status assessed prospectively using the Mini-Mental State Examination (MMSE); stereologic assessment of NFT, unaffected neurons, and total amyloid volume in the CAI field of the hippocampus, entorhinal cortex, and area 9. Statistical analysis was performed using both univariate and multivariate linear regression models. High total NFT counts but not amyloid volume were strongly associated with a lower number of unaffected neurons in all areas studied. A high proportion of variability in MMSE scores was explained by NFT and neuronal counts in the CAI field (83% and 85.4%), entorhinal cortex (87.8% and 83.7%), and area 9 (87% and 79%); amyloid volume in the entorhinal cortex, but not in the CA1 field and area 9, accounted for 58.5% of MMSE variability. Multivariate analyses showed that total NFT counts in the entorhinal cortex and area 9 as well as neuron numbers in the CAI field were the best predictors of MMSE score. (PsycINFO Database Record (c) 2004 APA, all rights reserved